Solid-state batteries show promise

When the gull-wing doors raised on the swoopy Lexus LF-30 Electrified concept car during its Tokyo Motor Show debut late last month, two words in bright blue letters could be seen on the car's threshold: "Solid State."

It was further evidence that Toyota is on track to keep a promise it made in 2017 to have solid-state batteries on the road by the mid-2020s.

These batteries use solid materials not only for the electrodes, but also for the electrolyte, normally a liquid or gel.

According to news reports, Shigeki Terashi, chief technology officer, told reporters before the Tokyo show that next year, Toyota will debut at the Tokyo Olympics a people-mover concept vehicle powered by solid-state batteries. Toyota, he said, expects solid-state batteries to begin mass production around 2025.

In the race to replace lithium ion in the next generation of electric car batteries, solid-state technology is gaining a lot of traction, not only at Toyota Motor Corp., but also with many other major automakers and battery suppliers, such as Japan's Panasonic Corp. and South Korea's LG Chem. Solid state just may have the magic formula that enables an almost seamless transition from internal-combustion engines to electric motors. Researchers know that to essentially replace gasoline the future electric car battery — regardless of its chemistry — must:

• Have immense power and density

• Be capable of ultrafast recharging
• Dramatically reduce the danger of fires
• Last the life of the vehicle
• Cost far less than lithium ion does today

• Affordably scale up to high-volume production.

"Certainly, the game has changed now," Joe LoGrasso, a director at the United States Advanced Battery Consortium, told Shift. "The Koreans and Japanese have a lot of development that looks promising. It's now a global race to get to the best solution."

Solid-state batteries appear to have the best potential to meet most of the objectives for a next-generation battery, experts say. More lab work tweaking the chemistry and more real-world testing will determine whether they really do have the right stuff.

In an interview with Bloomberg published last month, M. Stanley Whittingham, one of the three men awarded this year's Nobel Prize in chemistry for their work on lithium ion, acknowledged the potential of solid-state batteries but said he expects lithium ion to remain dominant for at least the next decade.

"Toyota Motor Corp. and a whole host of American companies are working on solid-state batteries, though it's not clear how much those will cost to manufacture, and it's not clear yet whether you'll get a decent amount of power. They may work for things like iPhones initially, but there are some big questions before they are used in larger-scale systems," he said.

General Motors is one of the U.S. companies working on solid state. During a Shift conference on batteries last month at Lawrence Technological University in suburban Detroit, Tim Grewe, director of GM's global electrification and battery systems, said GM is bullish on solid-state batteries.

"Solid state for me comes in two categories — electrolyte and anode. Both of them haven't earned their way in yet," Grewe said during a panel discussion, "but we are very encouraged with them, to say they offer better range and less mass. They look very promising, and we are developing those as fast we can."

But GM, Toyota, Honda Motor Co., other automakers and battery suppliers are also working on improving lithium ion batteries. And while solid-state batteries have great potential, Whittingham says there is still plenty of efficiency left to be gained by improving the chemistry of lithium ion batteries. "Right now, we only get 25 percent of theoretical capacity of them, so that's 75 percent that's dead volume or dead weight," Whittingham told Bloomberg. "It's the top folks in the world working on that project."

LoGrasso said: "As we look at the next generation of lithium ion batteries, they are going to include more nickel content in the positive electrode. We'll start adding more silicon to deal with fast-charging in the negative electrode. There is a lot of research going on into less flammable electrolytes to try to deal with the flammability threat."